The firmware does check. For a Cartesian, CoreXY or SCARA printer, make sure that you have the correct parameters in the M208 S0 and M208 S1 commands. For a delta printer, make sure that you have the correct B parameter in the M665 command.

in my S3D slicer setup plate size was twice bigger (as a mistake). that definitely produced wrong gcode and tried to print out-of-the-bed.
that made cube collapsed into line… that messy line was printing.

I have just re-tested movement limits on my delta, and they work. The firmware doesn't produce a warning when in FDM mode because it's quite common for the skirt to be outside the limits of the bed; but the firmware limits the movement to be within the bed radius - unless you have used M564 S0 to disable limit checking. You can send M564 with no parameters to enquire whether limit checking is currently enabled.

David, I just helped 2 people on my Slack channel in the last 2 days with exactly this problem. I think a simple warning message in the console would be a good idea to help diagnose issues. Even with an out of bound skirt, a message would give the user some clue as to what is going on.